Andreas mechwart



(No Model.)

A. MECHWART.

3 Sheets-Sheet 1.

AXIAL FLOW DOUBLE WHEEL TURBINE.

Patented Oct. 18, 1892 INVENTOR M W MZTTORNEY m: mums virus so, mum-wan, vusumemu, a. c

(No Model.) 3 Sheets-Sheet 2.

A. MEOHWART. AXIAL FLOW DOUBLE WHEEL TURBINE.

No. 484.601. Patented 0ct.'18, 1892.

Witnesses inventor:

(No Model.) I 3 Sheets-Sheet 3'. A. MECHWART. AXIAL FLOW DOUBLE WHEEL TURBINE.

No. 484,601. Patented Oct. 18, 1892.

Witnesses. Invenioz:

WM flzedrms fl/ecuarl m: mums Perms co., mum-m UNITED STATES PATENT OFFIC ANDREAS MEOHWART, OF BUDA-PESTH, AUSTRIA-HUNGARY.

AXIAL-FLOW DOUBLE-WHEEL TURBINE.

SPECIFICATION forming part of Letters Patent No. 484,601, dated October 18, 1892.

Application filed March 16, 1892. Serial No. 425,091- (No model.)

To all whom it may concern:

Be it known that I, ANDREAS lVIEOHWART, a subject of the King of Hungary, and residing at Buda-Pesth, Austria-Hungary, have invented new and useful Improvements in Axial-Flow Double-Wheel Turbines with Balancing Arrangement of the Suspended Vertibines requiring a descending current.

My invention consists in an upflow turbine provided with a double series of buckets of differential vertical reaction or resistance and having a supply-flume beneath the wheel and guides in said fiuine pitched to correspond with the different types of buckets in the Wheel above.

My invention also consists in certain means hereinafter described for applying a governing-valve to the series of buckets having the lowest vertical reaction or resistance without materially affecting the supporting function of the water, and also in other auxiliary features hereinafter described.

Referring to the accompanying drawings, in which similar letters of reference indicate corresponding parts throughout, Figure 1 is a vertical sectional elevation illustrating my invention; Fig. 2, a similar view illustrating a modification of Fig. 1. Fig. 3 is a top plan View of myimproved turbine-wheel. Fig. lis a top plan view of the water-guides for the same, the wheel being removed. Fig. 5 is a View taken on line 0000, Fig. 3, showing the respective inclinations of the guides to the outer crown of buckets. Fig. 6 is a view taken on the line y y, Fig. 3, showing the respective inclinations of the guides to the inner crown of buckets. Fig. 7 is a plan view, looking from below,showing the differential arrangement of the Water-guides and the valves controlling the same.

My invention applies more especially to axial-flow turbines having vertical shafts, in which a vertical pressure is exerted on the buckets of the working wheel, and which pressure is considerable when subject to a strong impulse of the inflowing water. The s0-called Girard or impulse turbines with back vanes exert a proportionally-less pressure on the buckets of the working wheel than the so-called Jonval or pressure turbines with strong reaction. In order to exercise the supporting function, the Jonval or pressure type of turbine would be most efficient for use in the practice of my invention. An important object, however, is to adapt to my invention the use of a governing-valve for regulating the speed of the turbine, which necessarily involves a variability in the admission of the motive water and consequent axial pressure on the wheel. Such variability of feed if applied to the entire wheel would obviously be detrimental to its operation when depending for support upon the force of the water.

In order to admit of the application of a governing-valve to my improved character of turbine, I provide a wheel having two systems or series of buckets, one within another. The one system is constructed so as to offer a high reaction or strong vertical pressure upon the wheel according to the principle of the Jonval or pressure turbine, while the other series are constructed according to the principle of the impulse turbines or so-called partial turbine with back vanes having a small reaction, and consequently less proportionate vertical pressure. The pressure-wheel or high-reaction series of buckets receives always full admission of water and is so adapted that its axial pressure is nearly equal to the load of the wheel and its shaft and the gears thereon, while the low-pressure buckets in a separate crown of the wheel are made subject to the control of the governingvalve.

The governingvalve is mounted on the lower side of the working wheel, and thus its own weight counteracts the upward pressure of the water, so that the valve is practically balanced and its friction reduced to the minimum.

Referring to the drawings, A represents the flume connected to a suitable head of water and terminating in a quarter-turn, which is surmounted by the water-guide box L and the turbine wheel D.

U is the tail-race, surrounding the terminus of the flume, its water-level lying at or below the lower edge of the wheel D. The shaft G is keyed to the wheel D and rests thereon through an interposed ring K. The waterguide box L furnishes a means of support for the bearing I of the journal H at the lower extremity of the shaft. As will be seen in the drawings, the weight of the shaft and wheel is in no wise sustained in the bearing I, the load being supported solely by the waterpressure.

I illustrate a double wheel of the character hereinbefore pointed out, wherein the outer crown of buckets F offers high reaction and the inner crown of buckets E ofiers low reaction or vertical pressure. The bucketsE and F lie obliquely in the wheel, and B and O are respective channels or water-guides conducting to them. The passages C F comprise a turbine of the J onval or pressure type, while the passages B Ecomprise aturbine of the socalled Girard or impulse type,as hereinbefore referred to. To the channels of the inner wheel, which exerts the lowest vertical pressure, I apply the governing-valve J, which is rotatively moved by means of a worm-shaft S, projecting through the wall of the flume, and a toothed segment H on the valve. The valve is fitted to rotate on the hub M and the stud N, projecting downward from the waterguide frame L, and is supported by an adjustable shoulder 0. Some of the inlets B are turned outwardly and some are turned inwardly, as indicated, so that their orifices occupy differential radial distances from the axis of the wheel. The faces of the valve J also occupy differential radial distances to correspond with the positions of the orifices which they are to cover. When the valve J is in one position,thereforenamely,that indicated-all of the orifices are open. When the valve is revolved or half turned, its faces will fully cover the openings B, and at intermediate positions the valve accordingly controls the flow of the water with variable admission to the interior crown of the wheel.

While I have only illustrated one diiferential arrangement of the waterguides and their respective valves, I do not limit myself to that particular arrangement, as there are other advantageous arrangements possible.

The velocity of the issuing stream passing through the orifices of the inner crown being accordingly different from that passing from the outer crown of the working wheel, means are provided for preventing disturbances in working by the partition-wall P, surmounting the doublewheeled turbine, presenting an outwardly-curved flange, in order to guide away the water passing through the inner crown above the water rushing through the outer crown. The same purpose is accomplished by the elevated step of the inner crown above the outer one, as illustrated in Fig. 2.

T represents a blow-0E pipe projected from the base of the flume A into the tail-race for the purpose of removing substances that may lodge in the turn of the flume, and said blow- 0E pipe is provided with asuitable stop-valve, as indicated, for the purpose.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. An upflow turbine water-wheel provided with a double series of buckets of difierential vertical reaction or resistance and a governing-valve for controlling the supply of water to theseries of said buckets having .the lowest vertical reaction or resistance.

2. An upflow turbine wheel having its buckets in plural concentric series of differential vertical reaction or resistance and waterguides in the flume beneath the wheel in corresponding series, said guides being pitched to correspond with the different types of buckets in the wheel above.

3. An upflow turbine wheel having its buckets in plural concentric series of difierential vertical reaction or resistance and waterguides in the flume beneath the wheel in corresponding series, said guides being pitched to correspond with the diiferent types of buckets in the wheel above and the inlets to the inner series of said guides occupying differential radial distances from the axis of the wheel.

4. An upflow turbine wheel having a double series of buckets and water-guides in the flume beneath the wheel, constructed in corresponding series, the said series of buckets and their respective water-guides comprising a compound turbine having differential vertical reaction or resistance, and a governing-valve for controlling the supply of water to the part of the wheel olfering the lowest reaction or resistance.

5. An upflow turbine wheel having its buckets in plural concentric series of differential vertical reaction or resistance and waterguides in the flume beneath in corresponding series, the inlets of said water-guides occupying difierential radial distances from the axis of the wheel, and a governing-valve for controlling the supply of water to the part of the wheel offering the lowest vertical reaction or resistance.

6. An upflow turbine water-wheel having its buckets in plural concentric series of differential vertical reaction or resistance,waterguides beneath the same in corresponding series, and a governing slide-valve seated upward on the under face of the guide of the series of buckets having the lowest vertical reaction or resistance, whereby the confining pressure of the water is counteracted by In testimony whereof I have, this 6th day of the weight of the valve, for the purpose de- February, 1892, signed my name to this speci- IO scribed. fication, in the presence of two subscribing 7. An upflow turbine water-Wheel having witnesses.

5 its buckets in plural concentric series, the

overflow-walls cf the respective series being Witnesses: located at difierent 1eve1s;for the purpose de- GERsTER OR6NY, scribed. WILLIAM DE MARlAssY.

ANDREAS MECHWART. 

